Low‐temperature sintered conductive silver patterns obtained by inkjet printing for plastic electronics

Abstract

Silver metal patterns onto plastic substrates have been obtained by inkjet printing with commercial ink based on silver nanoscale particles. Morphological characterization by scanning electron microscopy of spin-coating processed films indicates that a sintering treatment at 250• C for 30 min is enough to sinterize the silver metal nanoparticles. X-ray photoelectron spectroscopy characterization of sintered metal films shows that the sinterization is accompanied by a reduction of carbon surface concentration coming from carbon-containing chemical compounds present in the ink formulation. After sintering at 250• C for 30 min, the material shows typical electrical resistivity of 4.6 × 10 −6 cm (i.e. about three times the value of bulk silver).Printed test structures show typical resistivity after sintering at 250• C for 30 min in the range of 5-7 × 10 −6 cm. Copyright

Inkjet Printing of Microcomponents: Theory, Design, Characteristics and Applications

“…Furthermore, linear morphology from a number of droplets show more complicated than that of single dot, including individual-drop, scalloped, uniform, bulging, and stacked-coins formations, which are controlled by the delay and drop spacing as well (Soltman & Subramanian, 2008). As the evaporation and curing temperature involved (Biswas et al, 2010;Scandurra et al, 2010), their morphology formations will change dramatically with more complexity in geometry and structure that will be further discussed in next Section 4.…”

“…Mostly, with synthesis of nanoparticle metals instead of polymers for inks, the electrical properties of inkjet-printed conductors have been investigated recently in many researches (Fuller et al, 2002;Lee et al, 2005;Kang et al, 2010;Scandurra et al 2010). Because of the need for fusing the nanoparticles, those inkjet print of metal inks typically feature a sintering process at elevated temperature (> 100 °C) to reduce their porous portions of structure, in which the resistivity of printed materials can be as low as 5-7×10 -6 Ωcm (Scandurra et al 2010). Furthermore, this type of conductive elements can be commonly applied in flexible microelectronics that has been attracting many efforts in recent years (Perelaer & Schubert, 2010).…”

“…Based on the this kind of application, more persisting efforts were made within recent years about the improvement of ink formulas (Kim et al, 2009;Chang et al, 2011), surface treatments and characteristics (Koo et al, 2005;Chen et al, 2010), and large-area and active lighting (Bale et al, 2006). In a similar development way, more extensive studies for inkjet printing applications were also directed to other fields including biochips (Xu et al, 2005;Gutmann et al, 2005), optical microlenses (Nallani et al, 2006;Chen et al, 2009), microelectromechanical systems (Fuller et al, 2002;Cho et al, 2006;Alfeeli et al, 2008), and electronic components (Lee et al, 2005;Scandurra et al, 2010;Perelaer et al, 2010). Among them, many of the fundamental processes (e.g., surface treatments and droplet depositions) and components (e.g., inkjetprinted polymers and conductors) are in common with the present display applications, in particular the polymer light-emitting and liquid crystal displays (Katayama, 1999;Mentley, 2002;van der Vaart et al, 2005).…”

Laser Direct Writing of Conductive Silver Micropatterns on Transparent Flexible Double-Decker-Shaped Polysilsesquioxane Film Using Silver Nanoparticle Ink

“…[1][2][3][4][5] In view of these applications, micrometer-sized conductive features such as electrodes, conductive lines, conductive patterns, etc. on flexible plastic substrates are essential.…”

“…Inkjet printing has been used to fabricate conductive features of Cu, Ag, and Au on various plastic substrates using Ó 2015 The Minerals, Metals & Materials Society printable metal nanoparticle inks. 4,[6][7][8][9][10][11][12][13][14][15][16] In inkjet printing, the conversion of nonconductive precursor inks into their conductive counterparts has mostly been carried out by conventional heating in an oven or on a hot plate, usually requiring temperatures above 200°C. Such sintering temperatures >200°C are not compatible with common polymer substrates such as polycarbonate (PC) or poly(ethylene terephthalate) (PET) due to their low glass-transition temperature (T g ), and may interfere with the thermal properties of the polymer.…”